Rotary pivoted hammer



B. CAMPBELL.

ROTARY PIVOTED HAMMER.

APPLICATION FILED JUNEZB, 1920.

Patented Apr. 25, 1922.

UiNiTED STATES rarest orrics.

EDWARD,IB. CAMPBELL, OF ST. LOUIS, MISSOURI, ASSIG1\TOR TO WILLIAMSPATENT CRUSHER & PULVERIZER COMPANY, OF ST. LOUIS, MISSOURI, ACORPORATION OF MISSOURI.

ROTARY PIVOTED HAMMER..

Application filed June 28,

To all whom it may conoem Be it known that I, EDWARD B. CAMP- BELL, acitizen of the United States, resid-. ing at St. Louis, State ofMissouri, have invented certain new and useful Improvements in RotaryPivoted Hammers, of which the following is a specification.

This invention relates to certain new and useful improvements in rotarypivoted hammers, the peculiarities of Which will be fully described andclaimed.

The main object of my invention is the provision of a simple eflicientform of hammer that may be readily made from a commercial shape of barsteel and will operate "efficiently in a grinding mill on stock food orother materials.

In the accompanying drawing on which like reference letters indicatecorresponding parts, Fig. 1 represents a vertical sectional viewtransversely tothe shaft and just inside the end disc of a grinding millembodying my improvements; Fig. 2 a sectional 618: vation on the line 22 of Fig. 1 with part of the rotor shown in side view; and Fig. 3 adetail perspective view of the preferred form of my hammer.

The letter 'A designates a shaft for a grinding mill having a casing 13and a cage C. On the shaft is mounted a series of discs D through whichpass hammer rods E parallel to the shaft which pivot/ally support thehammers which in my preferred construction consist of a'shank portion'Fprovided with a pivotal hole G at one inner end and having the other endturned out substantially at right angles to the shank as shown at II.This turned-out end is there fore parallel to the pivotal axis ofrotation and when two pieces thus formed are placed with their shanksback to back and their bent out-ends H extending in opposite directions,they constitue a T-form of hammer as shown in Figs. 2 and 3. Thecentrifugal force acting upon the hammers when so mounted as inthe'figures will cause them to maintain their radial position and exceptunder extreme resistance of material being acted on, when they will flybackwards be- Specification of Letters Patent. Pate t d A 25. 1 22 1920.Serial No. 392,419.

tween the said discs D. It is preferred in order to keep the bent outhead ends in fixed alignment to fasten the shanks together, by a rivetI, at some point in the shanks between the pivot hole and the bentouthead ends. The rivet-holds the shank portlons firmly back to back andco-operates with the hammer rod to maintain the bentout head ends inalignment, without other connection between the two symmetrical" piecesforming the pivoted hammer. The rlvets should be countersunk to preventinterference of the ends with the disc plates D. I have shown a. rivetas constituting the only fastening means but other form of fastening maybe employed. When thus rlvetedor secured together as shown in Fig. 3,the rlgid T-form of hammer head is maintained by the rod and rivet, andproduces a slicing action by its bent out head ends and acts efficientlyupon the material being reduced.

In Fig. 2 the rows of hammers are alternately arranged so that thehammer in one row comes opposite the openings between the two hammers inthe next adjacent rows 21nd thus secure uniformity of grinding ac-Iclaim:

An improved rotary pivoted hammer consistlng of two symmetrical thinfiat bar elements forming shanks placed fiat side to flat side, and eachhavinga head bent out at substantially right angles to the flat side ofthe shank in opposite directions,said bent out head portions having thethin edge of the bar in one head aligned with the thin edge of the otherhead and forming a thin cutting edge one-half the thickness of thedouble shank,the inner ends of each shank having an open hole nea'r theinner end registering with an open holein the other adj acent shank forpivotal mounting, and means for binding said elements together soas tomove as a unit. r

In testimony whereof I have aflixed my signature.

EDWARD B. CAMPBELL.

